1  复制/etc/skel目录为/home/tuser1,要求/home/tuser1及其内部文件的属组和其它用户均没有任何访问权限。 

[root@localhost ~]# cp -r /etc/skel /home/tuser1

[root@localhost ~]# chmod -R 700 /home/tuser1

[root@localhost ~]# ls -ld /home/tuser1

drwx------. 4 root root 4096 Aug 27 15:57 /home/tuser1


2  编辑/etc/group文件,添加组hadoop。

[root@localhost ~]# echo "hadoop:x:1003:" >>/etc/group

[root@localhost ~]# tail -n1 /etc/group

hadoop:x:1003:


3  手动编辑/etc/passwd文件新增一行,添加用户hadoop,其基本组ID为hadoop组的id号;其家目录为/home/hadoop。

[root@localhost ~]# echo "hadoop:x:1003:1003:hadoop:/home/hadoop:/bin/bash" >>/etc/passwd

[root@localhost ~]# tail -n1 /etc/passwd

hadoop:x:1003:1003:hadoop:/home/hadoop:/bin/bash

[root@localhost ~]# id hadoop

uid=1003(hadoop) gid=1003(hadoop) groups=1003(hadoop)


4  复制/etc/skel目录为/home/hadoop,要求修改hadoop目录的属组和其它用户没有任何访问权限。

[root@localhost ~]# cp -r /etc/skel /home/hadoop

[root@localhost ~]# chmod 700 /home/hadoop

[root@localhost ~]# ls -ld /home/hadoop

drwx------. 4 root root 4096 Aug 27 16:22 /home/hadoop


5  修改/home/hadoop目录及其内部所有文件的属主为hadoop,属组为hadoop。

[root@localhost ~]# chown -R hadoop.hadoop /home/hadoop

[root@localhost ~]# ls -la /home/hadoop

total 28

drwx------.  4 hadoop hadoop 4096 Aug 27 16:22 .

drwxr-xr-x. 13 root   root   4096 Aug 27 16:22 ..

-rw-r--r--.  1 hadoop hadoop   18 Aug 27 16:22 .bash_logout

-rw-r--r--.  1 hadoop hadoop  176 Aug 27 16:22 .bash_profile

-rw-r--r--.  1 hadoop hadoop  124 Aug 27 16:22 .bashrc

drwxr-xr-x.  2 hadoop hadoop 4096 Aug 27 16:22 .gnome2

drwxr-xr-x.  4 hadoop hadoop 4096 Aug 27 16:22 .mozilla

[root@localhost ~]# chown -R hadoop:hadoop /home/hadoop

[root@localhost ~]# ls -la /home/hadoop

total 28

drwx------.  4 hadoop hadoop 4096 Aug 27 16:22 .

drwxr-xr-x. 13 root   root   4096 Aug 27 16:22 ..

-rw-r--r--.  1 hadoop hadoop   18 Aug 27 16:22 .bash_logout

-rw-r--r--.  1 hadoop hadoop  176 Aug 27 16:22 .bash_profile

-rw-r--r--.  1 hadoop hadoop  124 Aug 27 16:22 .bashrc

drwxr-xr-x.  2 hadoop hadoop 4096 Aug 27 16:22 .gnome2

drwxr-xr-x.  4 hadoop hadoop 4096 Aug 27 16:22 .mozilla


6  显示/proc/meminfo文件中以大写或小写S开头的行;用两种方式;

[root@localhost ~]# grep -i '^s' /proc/meminfo

SwapCached:            0 kB

SwapTotal:       2031612 kB

SwapFree:        2031612 kB

Shmem:              4004 kB

Slab:              86896 kB

SReclaimable:      20608 kB

SUnreclaim:        66288 kB

[root@localhost ~]# grep -i '^[Ss]' /proc/meminfo

SwapCached:            0 kB

SwapTotal:       2031612 kB

SwapFree:        2031612 kB

Shmem:              4004 kB

Slab:              86932 kB

SReclaimable:      20616 kB

SUnreclaim:        66316 kB


7  显示/etc/passwd文件中其默认shell为非/sbin/nologin的用户;

[root@localhost ~]# grep -v '.sbin/nologin' /etc/passwd |cut -d: -f1

root

sync

shutdown

halt

dingpengchao

user7

mageia

slackware

openstack

madriva

hadoop


8  显示/etc/passwd文件中其默认shell为/bin/bash的用户;

[root@localhost ~]# grep 'bin/bash' /etc/passwd |cut -d: -f1

root

dingpengchao

user7

mageia

openstack

madriva

hadoop


9  找出/etc/passwd文件中的一位数或两位数;

[root@localhost ~]# grep -o '\b[0-9]\{1,2\}\b' /etc/passwd

0

0

1

1

2

2

3

4

4

7

5

0

6

0

7

0

8

12

10

14

11

0

12

13

30

14

50

99

99

81

81

69

69

68

68

38

38

48

48

76

89

89

42

42

74

74

72

72



10  显示/boot/grub/grub.conf中以至少一个空白字符开头的行;

[root@localhost ~]# egrep '^[[:space:]]+' /boot/grub/grub.conf

root (hd0,0)

kernel /vmlinuz-2.6.32-642.el6.x86_64 ro root=UUID=98504afb-f211-4129-9a07-675cffc866b0 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-


sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

initrd /initramfs-2.6.32-642.el6.x86_64.img


11  显示/etc/rc.d/rc.sysinit文件中以#开头,后面跟至少一个空白字符,而后又有至少一个非空白字符的行;

[root@localhost ~]# egrep '^#[[:space:]]+[^[:space:]]+' /etc/rc.d/rc.sysinit

# /etc/rc.d/rc.sysinit - run once at boot time

# Taken in part from Miquel van Smoorenburg's bcheckrc.

# Check SELinux status

# Print a text banner.

# Only read this once.

# Initialize hardware

# Set default affinity

# Load other user-defined modules

# Load modules (for backward compatibility with VARs)

# Configure kernel parameters

# Set the hostname.

# Sync waiting for storage.

# Device mapper & related initialization

# Start any MD RAID arrays that haven't been started yet

# Remount the root filesystem read-write.

# Clean up SELinux labels

# If relabeling, relabel mount points.

# Mount all other filesystems (except for NFS and /proc, which is already

# mounted). Contrary to standard usage,

# filesystems are NOT unmounted in single user mode.

# The 'no' applies to all listed filesystem types. See mount(8).

# Check to see if a full relabel is needed

# Update quotas if necessary

# Initialize pseudo-random number generator

# Configure machine if necessary.

# Clean out /.

# Do we need (w|u)tmpx files? We don't set them up, but the sysadmin might...

# Clean up /var.

# Clean up utmp/wtmp

# Clean up various /tmp bits

# Make ICE directory

# Start up swapping.

# Set up binfmt_misc

# Boot time profiles. Yes, this should be somewhere else.

# Now that we have all of our basic modules loaded and the kernel going,

# let's dump the syslog ring somewhere so we can find it later

# create the crash indicator flag to warn on crashes, offer fsck with timeout

# Let rhgb know that we're leaving rc.sysinit


12  打出netstat -tan命令执行结果中以‘LISTEN’,后或跟空白字符结尾的行;

[root@localhost ~]# netstat -tan |egrep 'LISTEN[[:space:]]*$'

tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN      

tcp        0      0 127.0.0.1:631               0.0.0.0:*                   LISTEN      

tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      

tcp        0      0 :::22                       :::*                        LISTEN      

tcp        0      0 ::1:631                     :::*                        LISTEN      

tcp        0      0 ::1:25                      :::*                        LISTEN    


13  添加用户bash, testbash, basher, nologin (此用户的shell为/sbin/nologin),而后找出当前系统上其用户名和默认shell相同的用户的信息;

[root@localhost ~]# useradd bash && useradd tsetbash && useradd basher && useradd -s /sbin/nologin nologin

[root@localhost ~]# grep '^\([[:alnum:]]\+\b\).*\1$' /etc/passwd

sync:x:5:0:sync:/sbin:/bin/sync

shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown

halt:x:7:0:halt:/sbin:/sbin/halt

bash:x:3005:3008::/home/bash:/bin/bash

nologin:x:3008:3011::/home/nologin:/sbin/nologin

[root@localhost ~]# awk -F '[:/]' '$1==$NF{print$0}' /etc/passwd

sync:x:5:0:sync:/sbin:/bin/sync

shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown

halt:x:7:0:halt:/sbin:/sbin/halt

bash:x:3005:3008::/home/bash:/bin/bash

nologin:x:3008:3011::/home/nologin:/sbin/nologin